Inkjet printers have become increasingly sophisticated and can generate more complex images than before, including color photographic-quality images. Some inkjet printers have two or more pens, such as a high dye-load pen and a low dye-load pen, or multiple chambers within a single inkjet pen to handle a wide range of colors and hues. Differences in drop volume and/or drop weights between the pens, however, may cause noticeable color variations and/or hue shifts and generate images that do not accurately replicate desired colors.
Accordingly, an embodiment of the invention is directed to a method of calibrating a device having a first fluid source that ejects a first drop quantity and a second fluid source that ejects a second drop quantity. An embodiment of the method comprises printing a pattern having a first portion and a second portion, wherein the first portion is printed by the first fluid source and the second portion is printed by the second fluid source; obtaining a relationship between the first drop quantity and the second drop quantity from the pattern; and adjusting data used to determine quantities of fluid to eject from the first fluid source or the second fluid source based on the relationship between the first drop quantity and the second drop quantity.
Another embodiment of the invention is directed to a calibration apparatus for a device having a first fluid source that ejects a first drop quantity to form a first region and a second fluid source to eject a second drop quantity to form a second region. The apparatus comprises an optical sensor to generate output from scanning the first portion and the second portion; and a processor arranged to receive the output, wherein the processor includes a configuration to determine a relationship between the first drop quantity and the second drop quantity using the output.
The embodiments described above are not intended to be exhaustive and other aspects of the invention will be apparent to those skilled in the art after reviewing the drawings and the detailed description below.